RANDON Marine
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Ph.D. Student Theme(s) : Keywords: Sole, Connectivity, Spatial structuration, Tracers, Otolith microchemistry/morphometry, Mark-recapture, Genetic |
Current Position
Ph.D. Student, Ecology and Ecosystem Health research unit, Fisheries and Aquatic Ecology research groupResearch
Thesis
Spatial structuration and connectivity within a marine fish metapopulation: Contribution of a multi-tracers approach for the Eastern Channel stock of common SoleCurrent Research Topics
My thesis is directed by Olivier Le Pape and Elodie Réveillac of the Ecology and Ecosystem Health research unit of Rennes (France) and focused on the existence of potential spatial structuration of the Eastern Channel stock of common Sole. Currently, both stock assessment and management suppose a single and homogeneous population. Yet, an incorrect stock delineation and the exclusion of a potential spatial structuration could lead to bias in growth, productivity and natural and fishery mortalities estimates. Since few years, the Eastern Channel stock of Sole is overexploited and a spatial heterogeneity in resources quality has been pointed out by professionals. Therefore, a better understanding of the stock spatial structuration is crucial to enhance the assessment and management of common Sole in the Eastern Channel. Recent researches have already showed a relatively low degree of connectivity induced by larval and juvenile stages. However, any study has focused on the adult-mediated connectivity in the Eastern Channel.Consequently, my thesis aims at investigating the spatial structuration induced by adults using a multi-tracers approach. This original methodology will combine the use of natural tracers (otolith microchemistry and morphometry), genetic tracers (Single Nucleotid Polymorphism), and mark-recapture study. Investigation of spatial heterogeneity in density-at-age and growth will also be conducted. By coupling all these tracers, we hope we would be able to (1) delineate sub-units and (2) highlight the intensity and direction of exchanges between these sub-units.